71-627: The Houghton Highway is a 2.74 km (1.70 mi) reinforced concrete viaduct , the second bridge to be built across Hays Inlet at Bramble Bay connecting the cities of Redcliffe and Brisbane in Queensland , Australia (the first bridge was the Hornibrook Bridge ). The bridge, along with the third bridge, the Ted Smout Memorial Bridge , were the longest bridges in the country until 27 March 2013, when
142-434: A 500 m (1,600 ft) approach to the southern end of the bridge along mostly 90 km/h (56 mph) four-lane Deagon Deviation dual carriageway . This 500 m (1,600 ft) approach was previously 80 km/h along with the bridge, and became 60 km/h with it. The stated reason behind the reduced speed limit was to reduce crash incidents, therefore reducing delays and blockages. The reduced speed limit
213-453: A major role in the evolution of concrete construction as a proven and studied science. Without Hyatt's work, more dangerous trial and error methods might have been depended on for the advancement in the technology. Joseph Monier , a 19th-century French gardener, was a pioneer in the development of structural, prefabricated and reinforced concrete, having been dissatisfied with the existing materials available for making durable flowerpots. He
284-615: A media statement titled "Call for second bridge rejected" was issued by the Transport and Main Roads Minister on 11 July 2003. However, three months later the then Queensland Premier, The Hon Peter Beattie , issued a statement announcing a study into when a new Redcliffe bridge might be built. A reason for this change of stance included campaigning by the Redcliffe City Council and a study they commissioned into
355-587: A new bridge became a need for Redcliffe. In the next year, Hollis became involved in two scandals and the opposition called for his resignation. When the state government announced the duplication of the Houghton Highway in April 2005, the opposition suspected that Hollis was going to resign and stepped up their campaign against him. Hollis resigned for health reasons in July triggering a by-election , and
426-419: A reduction in its durability. Corrosion and freeze/thaw cycles may damage poorly designed or constructed reinforced concrete. When rebar corrodes, the oxidation products ( rust ) expand and tends to flake, cracking the concrete and unbonding the rebar from the concrete. Typical mechanisms leading to durability problems are discussed below. Cracking of the concrete section is nearly impossible to prevent; however,
497-725: A technique to reinforce the concrete. In terms of volume used annually, it is one of the most common engineering materials. In corrosion engineering terms, when designed correctly, the alkalinity of the concrete protects the steel rebar from corrosion . Reinforcing schemes are generally designed to resist tensile stresses in particular regions of the concrete that might cause unacceptable cracking and/or structural failure. Modern reinforced concrete can contain varied reinforcing materials made of steel, polymers or alternate composite material in conjunction with rebar or not. Reinforced concrete may also be permanently stressed (concrete in compression, reinforcement in tension), so as to improve
568-426: A well-chosen concrete mix will provide additional protection for many applications. Uncoated, low carbon/chromium rebar looks similar to standard carbon steel rebar due to its lack of a coating; its highly corrosion-resistant features are inherent in the steel microstructure. It can be identified by the unique ASTM specified mill marking on its smooth, dark charcoal finish. Epoxy-coated rebar can easily be identified by
639-415: Is a composite material in which concrete 's relatively low tensile strength and ductility are compensated for by the inclusion of reinforcement having higher tensile strength or ductility. The reinforcement is usually, though not necessarily, steel reinforcing bars (known as rebar ) and is usually embedded passively in the concrete before the concrete sets. However, post-tensioning is also employed as
710-658: Is a mixture of coarse (stone or brick chips) and fine (generally sand and/or crushed stone) aggregates with a paste of binder material (usually Portland cement ) and water. When cement is mixed with a small amount of water, it hydrates to form microscopic opaque crystal lattices encapsulating and locking the aggregate into a rigid shape. The aggregates used for making concrete should be free from harmful substances like organic impurities, silt, clay, lignite, etc. Typical concrete mixes have high resistance to compressive stresses (about 4,000 psi (28 MPa)); however, any appreciable tension ( e.g., due to bending ) will break
781-528: Is coating them with zinc phosphate . Zinc phosphate slowly reacts with calcium cations and the hydroxyl anions present in the cement pore water and forms a stable hydroxyapatite layer. Penetrating sealants typically must be applied some time after curing. Sealants include paint, plastic foams, films and aluminum foil , felts or fabric mats sealed with tar, and layers of bentonite clay, sometimes used to seal roadbeds. Corrosion inhibitors , such as calcium nitrite [Ca(NO 2 ) 2 ], can also be added to
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#1732779616713852-504: Is located across the bay from San Francisco . Two years later, El Campanil survived the 1906 San Francisco earthquake without any damage, which helped build her reputation and launch her prolific career. The 1906 earthquake also changed the public's initial resistance to reinforced concrete as a building material, which had been criticized for its perceived dullness. In 1908, the San Francisco Board of Supervisors changed
923-464: Is named after The Hon James 'Jim' Houghton , Member for Redcliffe (1960–1979) and speaker (1974–1979). Houghton resigned from parliament on 7 August, four months before the bridge opened. The all-concrete Houghton Highway consists of 99 spans atop of some 400 T-beams, supported close to sea level by headstocks connected to five octagonal piles each. A notable characteristic of the Houghton Highway until 2010, other than its significant length,
994-541: Is one in which both the compressive and tensile zones reach yielding at the same imposed load on the beam, and the concrete will crush and the tensile steel will yield at the same time. This design criterion is however as risky as over-reinforced concrete, because failure is sudden as the concrete crushes at the same time of the tensile steel yields, which gives a very little warning of distress in tension failure. Steel-reinforced concrete moment-carrying elements should normally be designed to be under-reinforced so that users of
1065-428: Is one in which the concrete element is only reinforced near the tensile face and the reinforcement, called tension steel, is designed to resist the tension. A doubly reinforced beam is the section in which besides the tensile reinforcement the concrete element is also reinforced near the compressive face to help the concrete resist compression and take stresses. The latter reinforcement is called compression steel. When
1136-430: Is one in which the tension capacity of the tension steel is greater than the combined compression capacity of the concrete and the compression steel (over-reinforced at tensile face). So the "over-reinforced concrete" beam fails by crushing of the compressive-zone concrete and before the tension zone steel yields, which does not provide any warning before failure as the failure is instantaneous. A balanced-reinforced beam
1207-579: Is the theoretical failure point with a certain probability. It is stated under factored loads and factored resistances. Reinforced concrete structures are normally designed according to rules and regulations or recommendation of a code such as ACI-318, CEB, Eurocode 2 or the like. WSD, USD or LRFD methods are used in design of RC structural members. Analysis and design of RC members can be carried out by using linear or non-linear approaches. When applying safety factors, building codes normally propose linear approaches, but for some cases non-linear approaches. To see
1278-446: Is transferred from the concrete to the bar interface so as to change the tensile stress in the reinforcing bar along its length. This load transfer is achieved by means of bond (anchorage) and is idealized as a continuous stress field that develops in the vicinity of the steel-concrete interface. The reasons that the two different material components concrete and steel can work together are as follows: (1) Reinforcement can be well bonded to
1349-639: The Macleay River Bridge opened in Kempsey , NSW . Originally built to duplicate the crossing capacity, almost immediately after opening it was converted to a three lane roadway with 'peak flow' lane control as a result of the proposed upgrading of the Hornibrook Bridge being deemed uneconomic. The intended crossing capacity was finally provided with the opening of the Ted Smout Memorial Bridge in 2010. With rising traffic levels on
1420-468: The tensile strength of concrete was improved by the reinforcing. Before the 1870s, the use of concrete construction, though dating back to the Roman Empire , and having been reintroduced in the early 19th century, was not yet a proven scientific technology. Ernest L. Ransome , an English-born engineer, was an early innovator of reinforced concrete techniques at the end of the 19th century. Using
1491-719: The 1890s, Wayss and his firm greatly contributed to the advancement of Monier's system of reinforcing, established it as a well-developed scientific technology. One of the first skyscrapers made with reinforced concrete was the 16-story Ingalls Building in Cincinnati, constructed in 1904. The first reinforced concrete building in Southern California was the Laughlin Annex in downtown Los Angeles , constructed in 1905. In 1906, 16 building permits were reportedly issued for reinforced concrete buildings in
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#17327796167131562-697: The City of Los Angeles, including the Temple Auditorium and 8-story Hayward Hotel. In 1906, a partial collapse of the Bixby Hotel in Long Beach killed 10 workers during construction when shoring was removed prematurely. That event spurred a scrutiny of concrete erection practices and building inspections. The structure was constructed of reinforced concrete frames with hollow clay tile ribbed flooring and hollow clay tile infill walls. That practice
1633-607: The English counties of Norfolk and Suffolk. In 1877, Thaddeus Hyatt , published a report entitled An Account of Some Experiments with Portland-Cement-Concrete Combined with Iron as a Building Material, with Reference to Economy of Metal in Construction and for Security against Fire in the Making of Roofs, Floors, and Walking Surfaces , in which he reported his experiments on the behaviour of reinforced concrete. His work played
1704-405: The Hornibrook Bridge while its proposed refurbishment was conducted. The initial deck layout (from west to east) consisted of two 3,700 mm (145.7 in) lanes , an 1,800 mm (70.9 in) shoulder or "breakdown lane", and a 1,900 mm (74.8 in) footway . With just a diminutive reinforced concrete kerb to separate pedestrians from 80 km/h (50 mph) passing traffic,
1775-407: The Houghton Highway as the number one "pain in the neck" with Queensland motorists. Some 1200 members responded to the survey, asking them to nominate problem roads and intersections in the state. Respondents identified problems including insufficient capacity, the tidal flow or an accident/breakdown on the bridge causing major congestion, an inappropriate speed limit (60 km/h (37 mph)), and
1846-551: The Minister apologised for extensive delays after the system failed when a council contractor cut both the main and back-up power supplies to the tidal flow system just before 10:00am. Evening peak hour traffic was severely disrupted and banked-up for several kilometres as the bridge fell into "safe mode" with one lane open in each direction for over 10 hours until Energex reconnected power at 8:00pm. Changes implemented after this incident included an improved back-up power supply that
1917-695: The actual available length is inadequate for full development, special anchorages must be provided, such as cogs or hooks or mechanical end plates. The same concept applies to lap splice length mentioned in the codes where splices (overlapping) provided between two adjacent bars in order to maintain the required continuity of stress in the splice zone. In wet and cold climates, reinforced concrete for roads, bridges, parking structures and other structures that may be exposed to deicing salt may benefit from use of corrosion-resistant reinforcement such as uncoated, low carbon/chromium (micro composite), epoxy-coated, hot dip galvanized or stainless steel rebar. Good design and
1988-461: The actual bond stress varies along the length of a bar anchored in a zone of tension, current international codes of specifications use the concept of development length rather than bond stress. The main requirement for safety against bond failure is to provide a sufficient extension of the length of the bar beyond the point where the steel is required to develop its yield stress and this length must be at least equal to its development length. However, if
2059-479: The behavior of the final structure under working loads. In the United States , the most common methods of doing this are known as pre-tensioning and post-tensioning . For a strong, ductile and durable construction the reinforcement needs to have the following properties at least: François Coignet used iron-reinforced concrete as a technique for constructing building structures. In 1853, Coignet built
2130-499: The bridge up to an acceptable standard, and its continued maintenance, would be far greater than original predictions. At the same time, the state government believed that Redcliffe's future growth would be in its western areas, and therefore the connections of Redcliffe to the Bruce Highway should receive more attention – the original land-based and much longer route to Brisbane before the Hornibrook Bridge opened in 1935. With
2201-543: The chief reasons for the failure of reinforcement bars in concrete. The relative cross-sectional area of steel required for typical reinforced concrete is usually quite small and varies from 1% for most beams and slabs to 6% for some columns. Reinforcing bars are normally round in cross-section and vary in diameter. Reinforced concrete structures sometimes have provisions such as ventilated hollow cores to control their moisture & humidity. Distribution of concrete (in spite of reinforcement) strength characteristics along
Houghton Highway - Misplaced Pages Continue
2272-756: The city's building codes to allow wider use of reinforced concrete. In 1906, the National Association of Cement Users (NACU) published Standard No. 1 and, in 1910, the Standard Building Regulations for the Use of Reinforced Concrete . Many different types of structures and components of structures can be built using reinforced concrete elements including slabs , walls , beams , columns , foundations , frames and more. Reinforced concrete can be classified as precast or cast-in-place concrete . Designing and implementing
2343-422: The compression zone of a concrete is inadequate to resist the compressive moment (positive moment), extra reinforcement has to be provided if the architect limits the dimensions of the section. An under-reinforced beam is one in which the tension capacity of the tensile reinforcement is smaller than the combined compression capacity of the concrete and the compression steel (under-reinforced at tensile face). When
2414-541: The concrete resists compression and reinforcement " rebar " resists tension can be made into almost any shape and size for the construction industry. Three physical characteristics give reinforced concrete its special properties: As a rule of thumb, only to give an idea on orders of magnitude, steel is protected at pH above ~11 but starts to corrode below ~10 depending on steel characteristics and local physico-chemical conditions when concrete becomes carbonated. Carbonation of concrete along with chloride ingress are amongst
2485-412: The concrete roof and floors in the two-story house he was constructing. His positioning of the reinforcement demonstrated that, unlike his predecessors, he had knowledge of tensile stresses. Between 1869 and 1870, Henry Eton would design, and Messrs W & T Phillips of London construct the wrought iron reinforced Homersfield Bridge bridge, with a 50' (15.25 meter) span, over the river Waveney, between
2556-416: The concrete, thus they can jointly resist external loads and deform. (2) The thermal expansion coefficients of concrete and steel are so close ( 1.0 × 10 to 1.5 × 10 for concrete and 1.2 × 10 for steel) that the thermal stress-induced damage to the bond between the two components can be prevented. (3) Concrete can protect the embedded steel from corrosion and high-temperature induced softening. Because
2627-478: The concrete, which occurs when compressive stresses exceed its strength, by yielding or failure of the rebar when bending or shear stresses exceed the strength of the reinforcement, or by bond failure between the concrete and the rebar. Carbonation, or neutralisation, is a chemical reaction between carbon dioxide in the air and calcium hydroxide and hydrated calcium silicate in the concrete. Bruce Highway Too Many Requests If you report this error to
2698-403: The cross-section of vertical reinforced concrete elements is inhomogeneous. The reinforcement in a RC structure, such as a steel bar, has to undergo the same strain or deformation as the surrounding concrete in order to prevent discontinuity, slip or separation of the two materials under load. Maintaining composite action requires transfer of load between the concrete and steel. The direct stress
2769-475: The duplication of the bridge, frustrated by the apparent lack of interest in the matter by the state government. Just over two months later, a state election was called, earlier than anticipated, for 7 February 2004. During the election campaign, the Liberal candidate, Terry Rogers , raised the issue of a new bridge to Redcliffe, and Hollis suffered a 10.5% swing but held on to the now-marginal seat . Suddenly
2840-403: The examples of a non-linear numerical simulation and calculation visit the references: Prestressing concrete is a technique that greatly increases the load-bearing strength of concrete beams. The reinforcing steel in the bottom part of the beam, which will be subjected to tensile forces when in service, is placed in tension before the concrete is poured around it. Once the concrete has hardened,
2911-568: The first concrete buildings constructed in the United States was a private home designed by William Ward , completed in 1876. The home was particularly designed to be fireproof. G. A. Wayss was a German civil engineer and a pioneer of the iron and steel concrete construction. In 1879, Wayss bought the German rights to Monier's patents and, in 1884, his firm, Wayss & Freytag , made the first commercial use of reinforced concrete. Up until
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2982-511: The first iron reinforced concrete structure, a four-story house at 72 rue Charles Michels in the suburbs of Paris. Coignet's descriptions of reinforcing concrete suggests that he did not do it for means of adding strength to the concrete but for keeping walls in monolithic construction from overturning. The, 1872–1873, Pippen building in Brooklyn stands as a testament to his technique. In 1854, English builder William B. Wilkinson reinforced
3053-660: The knowledge of reinforced concrete developed during the previous 50 years, Ransome improved nearly all the styles and techniques of the earlier inventors of reinforced concrete. Ransome's key innovation was to twist the reinforcing steel bar, thereby improving its bond with the concrete. Gaining increasing fame from his concrete constructed buildings, Ransome was able to build two of the first reinforced concrete bridges in North America. One of his bridges still stands on Shelter Island in New Yorks East End, One of
3124-405: The lack of consideration given by authorities to another bridge crossing. The original intention of the Houghton Highway was to provide two lanes of southbound traffic, with the Hornibrook Bridge to be refurbished to provide two lanes of northbound traffic, doubling original capacity. When the Houghton Highway opened, it initially provided one lane in each direction, intended to temporarily replace
3195-568: The late 1990s. In particular, vehicle breakdowns or accidents that resulted in the temporary closure of one or more lanes causing congestion and delays demonstrated the vulnerability of the situation. The Department of Main Roads undertook a further upgrade of the bridge's tidal flow system. Commissioned in 2002 at a cost of $ 1.8 million, this upgrade included the replacement of the overhead arrow and cross signals with brighter, LED displays, monitoring of traffic flows and conditions with supervision of
3266-824: The light green color of its epoxy coating. Hot dip galvanized rebar may be bright or dull gray depending on length of exposure, and stainless rebar exhibits a typical white metallic sheen that is readily distinguishable from carbon steel reinforcing bar. Reference ASTM standard specifications A1035/A1035M Standard Specification for Deformed and Plain Low-carbon, Chromium, Steel Bars for Concrete Reinforcement, A767 Standard Specification for Hot Dip Galvanized Reinforcing Bars, A775 Standard Specification for Epoxy Coated Steel Reinforcing Bars and A955 Standard Specification for Deformed and Plain Stainless Bars for Concrete Reinforcement. Another, cheaper way of protecting rebars
3337-520: The longer western route via the Bruce Highway. Labor's Ray Hollis won the seat of Redcliffe in the 1989 election of the Goss government and, except for a slim 0.5% lead in 1995, the seat of Redcliffe built-up with a safe Labor majority of 13.7% in 2001. Continuing disquiet about the bridge capacity, and calls for it to be duplicated or replaced, were persistently rejected by the government –
3408-438: The microscopic rigid lattice, resulting in cracking and separation of the concrete. For this reason, typical non-reinforced concrete must be well supported to prevent the development of tension. If a material with high strength in tension, such as steel , is placed in concrete, then the composite material, reinforced concrete, resists not only compression but also bending and other direct tensile actions. A composite section where
3479-656: The most efficient floor system is key to creating optimal building structures. Small changes in the design of a floor system can have significant impact on material costs, construction schedule, ultimate strength, operating costs, occupancy levels and end use of a building. Without reinforcement, constructing modern structures with concrete material would not be possible. When reinforced concrete elements are used in construction, these reinforced concrete elements exhibit basic behavior when subjected to external loads . Reinforced concrete elements may be subject to tension , compression , bending , shear , and/or torsion . Concrete
3550-541: The old bridge did. Modifications to the bridge commenced in March 1982, and were completed by 3 September the same year, at a total cost of $ 435,000. The upgrade included six gantries , eight switchable message signs, 54 traffic signals , two mast arms, 51 overhead lights, 12 emergency telephones , 27.5 km (17.1 mi) of power cable and 2 km (1.2 mi) of communication cable. A routine inspection of Houghton Highway in 1991 found an alkali-silica reaction in
3621-581: The opening of the Ted Smout Memorial bridge, the Houghton Highway was upgraded with a bitumen overlay and new variable speed limit signs. The reduced 60 km/h (37 mph) speed limit was lifted on 19 August 2011, returning to the original 80 km/h (50 mph). This marked the completion of its rejuvenation and, with the new bitumen surface, an improved ride quality was provided 31 years after it opened. Reinforced concrete Reinforced concrete , also called ferroconcrete ,
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#17327796167133692-448: The passivation of steel at the anodic oxidation sites. Nitrite is a much more active corrosion inhibitor than nitrate , which is a less powerful oxidizer of the divalent iron. A beam bends under bending moment , resulting in a small curvature. At the outer face (tensile face) of the curvature the concrete experiences tensile stress, while at the inner face (compressive face) it experiences compressive stress. A singly reinforced beam
3763-426: The pedestrian footway, addition of a third lane and a tidal flow arrangement to provide two lanes for peak traffic flow – southbound in the morning and northbound in the afternoon and evening (reversed on weekends). As breakdown lanes could not be provided, emergency telephones and overhead lighting were also fitted to the bridge at the same time. The Houghton Highway did not originally include overhead lighting, whereas
3834-412: The pre-stressed concrete piles. This reaction caused internal cracking of the concrete, and crumbling and spalling of the concrete leaving the reinforcing steel exposed to the marine environment. Approximately 500 piles were encased in concrete below the water surface and up to 500 mm (19.7 in) above the high water level. Above this point, an externally bonded carbon fibre reinforced polymer
3905-529: The promise of a new bridge was made by both parties; the government announced it had already started the survey and public consultation phase. The Liberal candidate, once again Terry Rogers, won the 20 August by-election, while Labor won the seat back in 2006. The duplication of the Houghton Highway consisted of a new bridge named the Ted Smout Memorial Bridge . It was officially completed on 11 July 2010 and open to southbound traffic on 15 July 2010. After
3976-520: The proposed refurbishment of the Hornibrook Bridge cancelled, in October 1982 the Department of Main Roads investigated modification of the Houghton Highway, only ten months after it opened. Facing an unintended situation where the new bridge as built would not deliver any increased capacity, the modification of the bridge was completed within twelve months. The modifications involved the removal of
4047-433: The reinforced concrete element is subject to increasing bending moment, the tension steel yields while the concrete does not reach its ultimate failure condition. As the tension steel yields and stretches, an "under-reinforced" concrete also yields in a ductile manner, exhibiting a large deformation and warning before its ultimate failure. In this case the yield stress of the steel governs the design. An over-reinforced beam
4118-581: The size and location of cracks can be limited and controlled by appropriate reinforcement, control joints, curing methodology and concrete mix design. Cracking can allow moisture to penetrate and corrode the reinforcement. This is a serviceability failure in limit state design . Cracking is normally the result of an inadequate quantity of rebar, or rebar spaced at too great a distance. The concrete cracks either under excess loading, or due to internal effects such as early thermal shrinkage while it cures. Ultimate failure leading to collapse can be caused by crushing
4189-474: The structure will receive warning of impending collapse. The characteristic strength is the strength of a material where less than 5% of the specimen shows lower strength. The design strength or nominal strength is the strength of a material, including a material-safety factor. The value of the safety factor generally ranges from 0.75 to 0.85 in Permissible stress design . The ultimate limit state
4260-501: The system data and view of the bridge by CCTV at the remote Traffic Management Centre in Woolloongabba , Brisbane. Operators were for the first time also able to close and open lanes as required from the remote location. The upgrade project suffered delays from "technical issues", resulting in the then Transport and Main Roads Minister, The Hon Steve Bredhauer , thanking Redcliffe residents for their patience. Six months later,
4331-454: The tension on the reinforcing steel is released, placing a built-in compressive force on the concrete. When loads are applied, the reinforcing steel takes on more stress and the compressive force in the concrete is reduced, but does not become a tensile force. Since the concrete is always under compression, it is less subject to cracking and failure. Reinforced concrete can fail due to inadequate strength, leading to mechanical failure, or due to
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#17327796167134402-465: The trial a success, using data that showed only three crashes in the nine-month trial period. The data did not include vehicle breakdowns on the bridge that would have involved delays from blocked lanes. Prior to the permanent speed limit being announced, a four-vehicle crash occurred with a motorist trapped in her car, closing the bridge in the evening peak for three hours, and again caused banked-up traffic for several kilometres and forced motorists to take
4473-466: The two-lane Hornibrook Bridge in the 1970s, the Department of Main Roads investigated the construction of another structure to increase capacity and cope with future demand. Authorisation by the department was given to construct a new bridge in 1977, and the new Houghton Highway opened on 20 December 1979, by the then Premier of Queensland, The Hon Sir Joh Bjelke-Petersen . The Houghton Highway
4544-412: The use of the footway was minimal. The bridge had a southbound breakdown lane, on the basis that the two-way traffic flow was only meant to be temporary. With the Hornibrook Bridge closed for refurbishment, engineers were able to make a closer examination to determine more clearly the extent of work required. They found that deterioration of the bridge was worse than first expected, and the cost to bring
4615-403: The water mix before pouring concrete. Generally, 1–2 wt. % of [Ca(NO 2 ) 2 ] with respect to cement weight is needed to prevent corrosion of the rebars. The nitrite anion is a mild oxidizer that oxidizes the soluble and mobile ferrous ions (Fe ) present at the surface of the corroding steel and causes them to precipitate as an insoluble ferric hydroxide (Fe(OH) 3 ). This causes
4686-436: Was applied, wrapping the column to cover the damage and contain and conceal the existing cracks. It was also believed that such composites offered re-strengthening and a protection of the piles through encapsulated resin during the lamination. The treatment work was completed in 2000, and the repairs and condition of the piles are continually monitored. Increasing traffic resulted in the bridge reaching its upgraded capacity in
4757-404: Was granted a patent for reinforcing concrete flowerpots by means of mixing a wire mesh and a mortar shell. In 1877, Monier was granted another patent for a more advanced technique of reinforcing concrete columns and girders, using iron rods placed in a grid pattern. Though Monier undoubtedly knew that reinforcing concrete would improve its inner cohesion, it is not clear whether he even knew how much
4828-402: Was initially trialled for nine months from September 2003 until June 2004, then extended for a further six months. The Redcliffe City Council did not support a 60 km/h speed limit trial, and requested the Minister for Transport and Main Roads to reduce the trial period to three months. The Minister replied, committed to the nine-month trial. In November 2004, the state government declared
4899-512: Was separate from the main supply, tighter controls on works near the bridge requiring approval by the Department of Main Roads, and a variable message sign on the Gateway Motorway at Deagon to warn motorists of delays and suggest taking the longer, western route to Redcliffe via the Bruce Highway. In 2003 the speed limit was reduced from 80 km/h (50 mph) to 60 km/h (37 mph). The reduced speed limit also included
4970-422: Was strongly questioned by experts and recommendations for "pure" concrete construction were made, using reinforced concrete for the floors and walls as well as the frames. In April 1904, Julia Morgan , an American architect and engineer, who pioneered the aesthetic use of reinforced concrete, completed her first reinforced concrete structure, El Campanil, a 72-foot (22 m) bell tower at Mills College , which
5041-495: Was the particularly rough surface and therefore ride quality. Each concrete span has a slight concave curve, so a distinct corrugated ride was felt when driving over the bridge. These ride characteristics were due to the absence of a bitumen overlay prior to 2010, when the bridge was upgraded in conjunction with the construction of the Ted Smout Memorial Bridge. In February 2004, an RACQ survey recognised
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